1. Field of the Invention
The present invention relates to an intake valve lift variable engine comprising: an engine body; a cylinder head; an intake valve which is disposed in the cylinder head and which is controlled to be open and close so as to regulate the amount of intake air; and an intake system having no throttle valve and connected to the cylinder head, and particularly to a device for treating blow-by gas from a crank case and purge gas purged from a canister.
2. Description of the Related Art
The Japanese Patent Application Laid-open No. 2005-9487 discloses an intake valve lift variable engine in which a throttle valve is not interposed in an intake system by regulating the amount of intake air sucked by opening/closing control of an intake valve.
In a conventional engine in which a throttle valve is provided in an intake system, a negative pressure is generated in the intake system downstream side from the throttle valve, so that it is possible to suck blow-by gas from a crank case and purge gas purged from a canister and transfer them into the intake system by using the negative pressure. Therefore, in the intake valve lift variable engine disclosed in the Japanese Patent Application Laid-open No. 2005-9487, generation of a negative pressure in the intake system can not be expected since the amount of intake air is regulated by opening/closing control of an intake valve.